WO2006087669A1

WO2006087669A1 - A cooling device and a control method thereof

Info

Publication number: WO2006087669A1
Application number: PCT/IB2006/050465
Authority: WO
Inventors: Alphan Samdan; Turgay Ercan
Original assignee: Arcelik Anonim Sirketi
Priority date: 2005-02-16
Filing date: 2006-02-13
Publication date: 2006-08-24
Also published as: EP1848937A1; RU2362949C2; CN101128711A; RU2007134350A; KR20070103450A; CN100538226C; KR100924733B1

Abstract

A cooling device (1) wherein the air circulation is realized in at least two different directions and the control method thereof.

Description

Description A COOLING DEVICE AND A CONTROL METHOD THEREOF

[001] The present invention relates to a cooling device wherein the air circulation is improved and a control method thereof.

[002] In state-of-the-art, the air in a cooling and/or freezing compartment is circulated within the compartment by the help of a fan to maintain a homogeneous distribution of heat. The air is preferably passed over the evaporator. The air that reaches its lowest temperature right after passing over the evaporator is heated as it circulates within the compartment. In consequence, the food items that the air contacts first after having left the evaporator are 3-4°C cooler than the food items that the air ultimately contacts. Thereupon, in order to cool the food that is at a distance from the air outlet, for example to -18°C, the food on the closer shelf has to be cooled down to -22°C. This is a factor which both reduces efficiency by prolonging the cooling time and increases energy consumption.

[003] In the state-of-the-art, changing the direction of the air flow in the compartment has been suggested as a solution to this problem. One of the embodiments of the state- of-the-art, the United States Patent no. US4736592, describes how the air in the container is made to flow in one direction for a certain period and then in the opposite direction by utilizing flaps. Raps are controlled by a timer or a heat sensor.

[004] In another embodiment in the current state-of-the-art, in the cooling device described in the European patent no. EP0862878, the direction of the air flow is reversed for certain periods. In this embodiment, a bi-directional fan is utilized to change the direction of the air flow.

[005] In state-of-the-art embodiments, changing the direction of the air flow according to time periods or the values read by a heat sensor situated at a point is insufficient for homogenizing the distribution of heat. For example, in a cooling device having a blower fan situated on the upper part of the compartment, if hot food is placed on the lower shelf, the temperature of the lower shelf will be higher compared to the upper shelf. Under this condition, the upper shelves will be cooled more as a result of the air blown from the upper part to the lower part, whereas the necessary cooling of the hot food on the lower shelf will be delayed.

[006] The aim of the present invention is to realize a cooling device and a control method thereof wherein the heat distribution within the compartment is controlled more efficiently and a fast cooling process is accomplished.

[007] The cooling device designed to fulfill the aim of the present invention is illustrated in the attached drawings, where:

[008] Figure 1 - is the side schematic view of a cooling device. [009] Figure 2 - is the front schematic view of a cooling device.

[010] Figure 3 - is the front schematic view of a cooling device in another embodiment.

[011] Figure 4 - is the front schematic view of a cooling device in yet another embodiment.

[012] Figure 5 - is the flow chart of a control method.

[013] Figure 6 - is the flow chart of another embodiment of the control method.

[014] Figure 7 - is the flow chart of a further embodiment of the control method.

[015] Figure 8 - is the flow chart of an alternative embodiment of the control method.

[016] Elements shown in figures are numbered as follows:

1. Cooling device

2. Compartment

3. Evaporator

4. Compressor

5. , 500. Fan

6. , 600. Sensor

7. Control unit

8. Channel

9. , 900. Orifice

[017] The cooling device (1) of the present invention comprises, a compressor (4) compressing the refrigerant fluid and circulating it in the refrigerant cycle,

- one or more compartments (2) where the food is stored for cooling and/or freezing purposes,

- at least one evaporator (3) which transmits heat from the medium to the refrigerant,

- at least one fan (5) which enables circulating the air within the compartment (2) in at least two different directions,

- at least two sensors (6, 600) measuring temperatures (TA, TB) situated at different points (A, B) in the compartment (2) and,

- a control unit (7) which determines the direction of the air flow (Fl, F2) by evaluating the temperatures (TA, TB) measured by the sensors (6, 600) and controls the fan (5) according to this choice (Figure 1).

[018] The control unit (7) compares the temperature values (TA, TB) measured by the sensors (6, 600) and provides the direction of the air flow (Fl, F2) to be such that the air, after sweeping past the evaporator (3), first reaches the higher temperature point within the compartment (2), by flowing from the comparatively higher temperature point towards the lower temperature point (in a clockwise or counterclockwise direction between A and B). The control unit (7) gathers information on the temperature values (TA, TB) measured by the sensors (6, 600) and, if necessary, about whether or not the compressor (4) is operating, and controls the fan (5) accordingly. The control unit (7) is electrically connected to the compressor (4), the sensors (6, 600) and the fan (5) to this end.

[019] In one embodiment of the present invention, the compartment (2) comprises a channel (8) in which the evaporator (3) and the fan (5) are situated and at least two orifices (9, 900) for allowing air to enter and exit from this channel (8). The air flow (Fl, F2) enters the channel (8) from one orifice (9), flows above the evaporator (3), and leaves the channel (8) from the other orifice (900).

[020] In the preferred embodiment of the present invention, the change of direction of the air flow (Fl, F2) is provided by a fan (5), positioned in the compartment (2), preferably in the channel (8), which can circulate the air in the clockwise (Fl) and in the reverse (F2) direction within the compartment (2) (Figure 2).

[021] In yet another embodiment of the present invention, the direction of the air flow

(Fl, F2) is provided by two fans (5, 500) side by side, whereby one of the fans circulates the air in only clockwise direction (Fl) and the other in only counterclockwise direction (F2) (Figure 3). The air passing over the evaporator (3), for example, first reaches A (Fl) when only the first fan (5) operates, and first reaches B (F2) when only the second fan (500) operates. The two fans (5, 500) do not operate concurrently in order to have the air flow (Fl, F2) create a circulation within the compartment (2).

[022] In another embodiment of the present invention, two fans (5, 500) are positioned at different points within the compartment (2), one of the fans circulating the air only in a clockwise (Fl) direction and the other in the counter clockwise direction (F2) (Figure 4). For example, if the upper fan (5) can circulate the air in a clockwise direction (Fl), and the lower fan (500) can circulate in a counterclockwise direction (F2), the air which passes over the evaporator (3), will first reach A (Fl) when only the first fan (5) operates, and will first reach B (F2) when only the second fan (500) operates.

[023] The control unit (7) of the cooling device (1) of the present invention functions according to the method given below: comparing (101) the temperatures (TA, TB) measured at two different points (A, B); controlling (102, 103) the fan(s) (5, 500) so that the air flows in a direction (Fl, F2) wherein the air first reaches the point that is hotter (from A to B or from B to A) after sweeping the evaporator (3).

[024] In this embodiment of the method (100) of the present invention, if the temperature

(TA) at point A is greater than or equal to (TAfU TB) the temperature (TB) at point B, the air is circulated (102) from A to B. However, if the temperature (TB) at point B is greater than (TB>TA) the temperature (TA) at point A, the air circulates (103) from B to A (Figure 5).

[025] In another embodiment of the present invention, before comparing (101) the temperatures (TA, TB), the compressor (4) is controlled (105) for whether it is operating or not, if it is not operating, air flow (Fl, F2) stops (106) and the step wherein comparing (101) the temperatures (TA, TB) is carried out only after the compressor (4) starts operating (Figure 6).

[026] In yet another embodiment of the present invention, if the cooling device (1) is operating for the first time, the first direction of the air flow (Fl, F2) after the compressor (4) starts operating, is a direction determined by the producer, for example from A to B. But if the cooling device (1) is not operating for the first time, the first direction of the air flow (Fl, F2) after the compressor (4) starts operating is the direction when the compressor (4) last operated.

[027] In yet another embodiment of the present invention, after comparing (101) the temperatures (TA, TB), their difference (ITA-TBI) is checked (107 and 108) for whether it exceeds a value (DTl or DT2) set by the producer, and the direction of the air flow is not changed (104) as long as this value is not exceeded. For example, if the temperature (TA) at point A is higher than (TA>TB) the temperature (TB) at point B, the difference of the two temperatures (TA-TB) is checked (107) for whether it exceeds a value (DTl) set by the producer. The direction of the air flow is not changed (104) as long as this value (DTl) is not exceeded, and the direction of the air flow is changed after this value (DTl) is exceeded (Figure 7). If the temperature (TA) at point A is lower than (TA<TB) the temperature (TB) at point B, the difference of the two temperatures (TB-TA) is calculated. This difference is compared (108) to a value (DT2) set by the producer. While the said difference is below this value (DT2), the direction of the air flow is not changed (104). If the said difference is above this value (DT2), the flow is changed (102) to the reverse direction. The DTl and DT2 values can be equal or different from each other.

[028] In yet another embodiment of the present invention, a threshold value (TAC, TBC) is assigned to each one of the sensors (6, 600) and the values read are compared (109, 110) not to each other but to these values, if these threshold values are exceeded, the air flow after the evaporator (3) is directed so that it first reaches to the point where the threshold value is exceeded. For example, if the temperature value (TA) read by the first sensor (6) exceeds the threshold value (TAC) assigned to this sensor (6) (TAfUTAC), the direction of the air flow is decided to be from A to B (Fl). But if it is below this value (TA<TAC), the temperature (TB) measured by the other sensor (600) is checked (110) for whether it exceeds the threshold value (TBC) of this sensor (600). If it is exceeded (TB fU TBC), the air circulation (F2) is from B to A (103), otherwise the circulation direction is from A to B (102) (Figure 8).

[029] When hot food is placed on the upper shelf in the cooling device (1) of the present invention, the value (TA) measured by the sensor (6) on the upper shelf will be higher (TA>TB) than the value (TB) measured by the sensor (600) on the lower shelf. In this case, the control unit (7) operates the upper fan (5) which can circulate the air both clockwise and counter clockwise (Figure 2), so that the air flow is from A to B (Fl). The hot food on the upper shelf will cool rapidly since the air passing over the evaporator will first reach the upper shelf. But if the hot food is placed on the lower shelf, the value (TB) measured by the sensor (600) on the lower shelf will be higher (TA<TB) than the value (TA) measured by the sensor (6) on the upper shelf and the control unit (7) will circulate the air from B to A (F2), the food on the lower shelf will cool since cold air will first flow through the lower shelf.

[030] In the cooling device (1) of the present invention, the temperature of the compartment (2) is controlled in more points by positioning the sensors (6, 600) and the fan(s) (5, 500) suitably, creating an air flow which ensures that cool air reaches first of all the required region . Consequently the speed and efficiency of cooling is enhanced, and energy consumption is reduced.

Claims

[001] A cooling device (1) comprising; a compressor (4) compressing the refrigerant and circulating it in the refrigerant cycle; one or more compartments (2) where the food is stored for cooling and/or freezing purposes; at least one evaporator (3) which transmits heat from the compartment (2) to the refrigerant fluid; at least one fan (5, 500) which enables creating an air flow (Fl, F2) within the compartment (2) in at least two different directions; and characterized by; at least two sensors (6, 600) situated at different points (A, B) in the compartment (2) for measuring temperatures (TA, TB); and a control unit (7) which determines the direction of the air flow (Fl, F2) by evaluating the temperatures (TA, TB) measured by the sensors (6, 600) and controls the fan(s) (5, 500) according to this choice.

[002] A cooling device (1) as in Claim 1, characterized by the control unit (7) which compares the temperatures (TA, TB) measured by the sensors (6, 600) and by the help of the fans (5, 500) provides the direction of the air flow (Fl, F2) to be such that the air, after sweeping past the evaporator (3), first reaches the higher temperature point within the compartment (2) by flowing from the comparatively higher temperature point towards the lower temperature point (in a clockwise direction or vice versa between A and B).

[003] A cooling device (1) as in any one of the above claims, characterized by the compartment (2) comprising a channel (8) into which the evaporator (3) and the fan (5, 500) are situated, and at least two orifices (9, 900) for the air to enter and leave this channel (8).

[004] A cooling device (1) as in any one of the above claims, characterized by a fan (5) situated in the compartment (2) which can circulate the air within the compartment (2) both in the clockwise direction (Fl) and the counterclockwise direction (F2).

[005] A cooling device (1) as in any one of the Claims 1 to 3, characterized by two fans (5, 500), situated inside the compartment (2) side by side, one of the fans circulating the air in only the clockwise direction (Fl) and the other in only the counterclockwise direction (F2), to provide change in the direction of the air flow.

[006] A cooling device (1) as in any one of the Claims 1 to 3, characterized by two fans (5, 500), situated at different points inside the compartment (2), one of the fans circulating the air in only the clockwise direction (Fl) and the other in only the counterclockwise direction (F2), to provide change in the direction of the air flow. [007] For a cooling device (1) as in any one of the above claims, a method comprising the steps of comparing (101) the temperatures (TA, TB) measured at different points (A, B), and controlling (102, 103) the fan(s) (5, 500) so that the direction of the air flow (Fl, F2) is from the hotter point to the other (from A to B or from B to A).

[008] A method as in Claim 7, characterized by the step wherein it is controlled whether the compressor (4) is operating or not before comparing (101) the temperatures (TA, TB), if not operating the fan(s) (5, 500) and the air flow (Fl, F2) are stopped (106), and the step (101) wherein the temperatures (TA, TB) are compared only after the compressor (4) starts operating.

[009] A method as in Claim 8, characterized in that if the cooling device (1) is operating for the first time, the first direction of the air flow (Fl, F2) after the compressor (4) starts operating is the direction determined by the producer.

[010] A method as in Claims 8 and 9, characterized in that if the cooling device (1) is not operating for the first time, the direction of the air flow (Fl, F2) is determined as the preceding direction.

[011] A method as in any one of the Claims 7 to 10, characterized in that after comparing (101) the temperatures (TA, TB), their difference (ITA-TBI) is checked (107 and 108) for whether it exceeds a value (DTl or DT2) set by the producer, and the direction of the air flow does not change (104) as long as this value is not exceeded.

[012] A method as in any one of the Claims 7 to 10, characterized in that instead of the step of comparing the measured temperatures (TA, TB) with each other (101), a threshold value (TAC, TBC) is assigned to each one of the sensors (6, 600), if these threshold values are exceeded, the air flow after passing the evaporator (3) is directed so that it first reaches the point where the threshold value is exceeded.